1. Field of the Invention
The present invention relates to a cloned single-strand DNA encoding amino acid sequence for a eukaryotic transcription factor S-II, a cloned double-strand DNA consisting of the single-strand DNA and its complementary single-strand DNA, a DNA fragment of the single- or double-strand DNA, a process for the preparation thereof, a plasmid, in which the double-strand DNA or its fragment is inserted, and a diagnostic reagent for the detection of diseases and more particularly viral diseases and cancers.
2. Related Arts
A transcription factor S-II is a protein, which was first separated and isolated by the present inventor from an Ehrlich ascites tumor cell and which shows a promotion of accuracy and efficiency of transcription through an eukaryotic RNA polymerase II ["Mol. Cell. Biochem." Vol. 46, pages 173-187 (1982)]. Thereafter, the same transcription factor has also been isolated from a bovine thymus suggesting that the substance is the factor commonly presents in eukaryotic cells ["J. Biol. Chem." Vol. 262, pages 5227-5232 (1987)].
In connection with a diagnosis of viral diseases and cancers, and more particularly the acquired immune deficiency syndrome (AIDS) among the virus diseases, a diagnosis using an antibody to HIV has generally been employed. Retroviruses such as HIV has been known to replicate using host RNA polymerase II. Besides RNA polymerase II, it is widely acknowledged that various cellular factors play a roll in eukaryotic transcriptional controls.
It has been apparent, as referred to, that the transcription factor S-II is present in eukaryotic cells, but its structure has not been elucidated. According to the prior arts, further, the transcription factor S-II has been prepared by separation and extraction from the cells and thus the preparation thereof in large amount was difficult.
While, various methods have been proposed to use a certain antibody for making a diagnosis of viral diseases and cancers and, more particularly, in the diagnosis of AIDS, such an antibody diagnosis is not always conclusive and there is no subsidiary diagnostic method, which sometimes makes impossible rather than difficult an exact diagnosis, such as when an antigen-antibody reaction shows a false positive.